Using an EST (expressed sequence tag) approach, we have been able to identify greater than 965 gene clusters from Wuchereria bancrofti microfilariae based on1687 ESTs. Interestingly, a surprisingly high percentage (584/965; 60%) of these clustered ESTs contain a putative signal peptide, and only 6 appear to be GPI anchored. When compared to Brugia malayi (Bm) mf ESTs/Clusters, 45% of the Wb clusters had matches to Bm ESTs (identities ranging from 86-100%) whereas fewer (22%) matched Onchocerca volvulus (Ov) mf ESTs (with identities ranging from 80-100%). A similar approach has been taken with Strongyloides stercoralis with >10000 ESTs being done from two separate lifecylcle stages. Comparisons between this parasitic nematode and the free-living C. elegans has been perfomed; the data demonstrate the vast differences in gene expresssion between parasitic and non-parasitic nematodes (Mitreva, DM, McCarter, JP. Marin, J, Dante, M, Wylie, T, Chipelli, B, Pape, D, Clifton, SW. Nutman, TB, Waterston, RH. Comparative Genomics of Gene Expression in the Parasitic and Free-living Nematodes Strongyloides stercoralis and Caenorhabditis elegans. Genome Res 14: 209-220, 2004).